Straw-plait-sewing machine.



E. WISEMAN.

STRAW PLAIT SEWING MACHINE.

APPLICATION FILED AUG-30. 1913.

1,137,249. Patented Apr. 27, 1915.

Fig/Q 2 SHEETS-SHEET I- THE NORRIS PETERS CO, FHDTO-LITHO. WASHINGTON D. t

E. WISEMAN.

STRAW PLAIT SEWING MACHINE.

APPLICATION FILED AUG-30. 1913.

1,137,249. 7 Patented Apr. 27, 1915.

2 SHEETS-SHEET 2- THE NORRIS PETERS 50.. FHOTOLITHOH WASHINGTON. D4 C.

ETNTTED TATE PATENT @FFTQE.

EDMUND WISEMAN, OF LU'TON, ENGLAND.

s'rnAw-PLArr-sEwING MACHINE.

in implements or needles attached to a carrier beneath the work plate are thrust upward 7 through the work and cooperate with one or more looping devices supported above and movable with the presser foot. Sewing inachines of this class are described in the specifications to my U. S. A. Patents Nos. 228711 of June 8, 1880, and 565585 of August 11, 1896 also in Johnsons British Patent No. 5926 of May 1, 1886.

My invention relates more particularly to sewing machines of the kind above set forth in which controller mechanism is employed for automatically varying the needle stroke according to the thickness ofv the work, said mechanism comprising a controller lever operated by the movement of the presser arm and connected with the needle operating mechanism, so as to vary the needle stroke .by its movement, and means for clamping or looking this lever during the passage of the needles through the work. Controller mechanism of this character is described in my said Patent Number 565585 and also in Johnsons said British patent.

The object of my invention is to insure the production of work of better quality and much firmer texture, by causing the stitch to be more perfectly drawn up than heretofore, and to this end my invention relates to improvements in the means heretofore used for locking the said controller mechanism. The means heretofore used for clamping or looking the controller mechanism was liable to slip at times, as for example when the work offered considerable resistance to the passage of the needles, the drawing up of the stitch and consequent firmness of the work sewn being consequently affected. My improved locking means is designed to eliminate risk of slipping and to give an absolute locking Specification of Letters Patent.

' swings.

Patented Apr. 2%, 1915.

Application filed. August 30, 1913. Serial No. 78?,511.

of the controlling mechanism under all working conditions, and by its use a change in the character of the stitch is produced, the stitch being better drawn up and firmer work of superior quality resulting.

According to my invention the means which I employ for locking the controller mechanism at the proper periods comprises an are shaped member or sector, called the locker arc, carried by the controller lever and arranged in a plane parallel with its plane of movement, said are being struck from the center about which said lever An arm mounted on a rock shaft or pivot and called the locker rocker, carries a block, called the locker clamping block, having a contact surface curved to coincide with the curve of said arc. The locker rocker is operated from some suitable moving part of the machine, the needle eccentric will be found convenient, so as to cause the locker clamping block to engage and grip the locker are at the proper periods. The locker clamping block is mounted on a pin or pivot on the locker rocker soas to be able to rock slightly in the plane of the locker arc, it will thus accurately adjust itself to the curve of this are. a

The means for operating the locker rocker are connected with the free end of a yielding spring steel arm or lever rigidly secured to said locker rocker. This spring arm provides the necessary yield or give in the locking means, and when by reason of stress applied to its free end it holds the locker clamping block in contact with the locker arc, any tendency of the latter to slip is promptly followed up by said spring arm, so that the clamping block and locker are are always held in close contact. The said spring arm must be of suflicient strength to give positive movement to the locker rocker when the locker clamping block is out of contact with the locker arc, and to hold the controller lever firmly'locked when said are and clamping block are in contact.

The pivot of the controller lever, the pivot on which the locker clamping block rocks, and the pivot or rock shaft of the locker rocker are so relatively arranged as to constitute the fulcra or pivotal points of a toggle, and as a result, when the locker clamping block is held in contact with the locker arc by the means above described any stress due to resistance of the work to the passage of the needles, which-would tend to move the controller lever, tends to move these pivots into line, whereby a toggle action is obtained which causes the grip of the locker clamping block on the locker arc to increase in direct proportion to such stress. The said locker arc may be integral with or rigidly secured to the controller lever, but in order to in- 7 sure absolute and perfect contact between all points of the contacting surfaces of said are and the locker clamping block, the locker arc is preferably so mounted on the controller lever as to be capable of a slight rocking motion in a plane at right angles to the plane in which the clamping block rocks. The locker are and the locker clamping lock being thus both capable of slight rock or'play in planes at right angles, absolute and eiiicient contact between them is assured.

For convenience in assembling the machine, provision may be made, such as hereinafter described, for fine adjustment of the locker clamping block so as to regulate the distance between its contact surface and that ofthe locker are.

In the annexed drawings in which similar letters refer to like parts in all the figures: Figure 1 is a part sectional plan view showing a sewing machine of the kind described embodying my mprovements, those parts of the machine not necessary for a clear understanding of the invention being omitted. Fig. 2 is a sectional end view looking from the right hand of Fig. 1, showing clearly the controller mechanism and my improved means for locking the same. Fig. 3 is a transverse section on line 33,Fig. 1 showing the tension cam and tension proper and the hand operated means for varying the degree of tension. Fig. 4 is a part front view of Fig. 1. Figs. 5, 6 and 7 aredetails showing the locker arc in side view, plan and end view, respectively. Fig. 8 is a section on line 88 Fig. 5. Figs. 9 and 10 show the locker rocker in side View and plan respectively. Fig. 11 is a section on line l1ll Fig. 9. Figs. 12 and 13 show in side View and plan respectively a slightly modified construction of locker rocker; Figs. 5 to 12 inclusive are drawn to a slightly larger scale. 5

I will first describe my improved means for locking the controller mechanism, the controller mechanism illustrated being similar to that described in my said Patent Number 565585, and to facilitate identification of the parts shown in my drawings and described in my said former specification I have designated them by reference letters corresponding with those in the drawings of mysaid former specification.

f is the controller lever pivoted at f to the rocker arm in whose function as described in my said patent is to counteract or neutralize the movement of the controller lever by the feed devices, said lever having its'arm f connected by the link 9 with the 7 two part lever I secured on the rock shaft e of the presser arm.

7 is the link connecting the lower end of the controller lever with the block 0 s'lidable in the slotted rocking arm 0 which reciprocates the needle carrier by the link 0 said" arm being vibrated from the needle eccentric a by means of the link a operated by the said eccentric and connected with the block 0.

z is an are shaped member carried by thev pin received. in grooves formed in the part 2' of the controller lever and in the locker are respectively. Surrounding the ends of the grooved portions in said part 2' and the locker are are semicircular flanges 2' and split spring washers i passed round these flanges hold the arc to the said part so that it floats on the interposed stud pin. rjndwise movement of the arc relatively to the ;part i is prevented by the washers i fixed on stud pin and fitting within slots formed in the arc and in the part On the rock shaft mounted inbearings in the machine casing is fixed the locker rocker m which carries the locker clamping block m, adapted to contact with the locker arc and having its contact surface curved to correspond therewith. This clamping block is free to rock in the plane of movement of the locker are, being floated on the stud pin M in a similar manner to the locker are as clearly seen in Figs. 9 to 11.

Rigidly attached to the locker rocker m is the spring steel operating arm or lever n whose free end is connected with one end of the link a, whose other end is connected at n with the tie rod 4& one end of which works on the fixed pivot a while its other forked end is connected with the link a to hold the same in position on the strap of the needle eccentric a. Vibrating movement is thus imparted to the tie rod a by the needle eccentric a. By this means the locker rocker is actuated from the needle eccentric at thev the'members of a togglewhe'n any stress due to the resistance of thework to the passage of the needles is applied to the controller lever, such stress tending to move the said thus obtained it follows that the grip of the locker clamping block upon the locker arc will be increased in direct proportion to such a stress.

For facility of'adjustment in assembling the machine the locker rocker may be made as shown in Figs. 9 to llirrtwo portions hinged together at m and adapted to be set more or less apart by the adjusting screw m*, m being a spring whose .free end engages an inclined slot in the upper part of the rocker and thus tends to keep this upper part in contact with the adjusting screw. The fine adjustment afl'orded by this screw permits the clamping block to be accurately adjusted relatively to the locker are. In the modified construction of locker rocker shown in Figs. 12 and 13, in lieu of making the rocker in two parts hinged together, the

block m which carries the floatingclamping block m is secured to the rocker by the screws m and adjustment of the clamping block is effected by means of distance washers m To facilitate an understanding of the operation of the invention, Ivwill briefly describe a form of intermittent thread tension mechanism in connection with which the invention may be employed.

J is a tension cam moved laterally on the main shaft D by the lever N, see Figs. 1 and 3, and adapted to shift the position of the variable feed eccentric M to change the length of stitch by means of the lever 107 in the known manner.

88 is the tension lever whose roller is held spring pressed against the cam J, and 809 is a screw carried by lever 88 the end of which screw at the proper times is caused to strike the end of the tension stud 84: and open the tension, also in the known manner.

The tension proper shown in the drawings is similar to that shown in Johnsons said British specification, but in lieu of connecting the pin 228, which extends from the sliding sleeve 81 of the tension through a slot in the sleeve boss, by a link with an arm of the tension cam shifting lever N, I pivot inside the casing of the machine a lever 0 carrying at its free end an incline o adapted to bear on the said pin 228 of the sliding sleeve 81, and to the exterior of the casing I pivot the hand lever 10. A pin p extends from the lever 0 through a slot in the casing and engages in a notch in the lever 32,

position, the end wall of theslot in the casing constituting a stop to limit its movement, the original degree of tension determined by the screw tensionstud 84 will be restored.

WhatI claim and desire to secure by Letters Patent of the United States is 1. A sewing machine, embodying therein needle operating mechanism,

lever, and means for locking said lever comprising a member carried by said lever and capable of rocking slightly in a plane at rightangles to that in which the said lever moves, a block operatively related to said member, and means for periodically forcing said block into direct engagement with said member.

2. A sewing machine, embodying therein needleoperating mechanism, controller mechanism therefor including a controller lever, and means for locking said lever comprising an are shaped member on the lever and capable-of rocking slightly in a plane at right angles to thatin which the said lever moves, a block having a curved face adapted toengage said member, and means for periodically forcing the curved face of said block into direct engagement with the troller lever, a locking member on said lever, a pivoted block adapted to engage said locking member, and pivoted means for periodically forcing said block into engagement with said member, the pivots of said lever, block and last named means being adapted to be moved into line with each other when said controller lever is moved during engagement between said member and said block.

4. A sewing machine, embodying therein needle-operating mechanism, controller mechanism therefor including a controller lever, a locking member carried by said lever, means for securing the member to the lever so that said member is capable of a slight rocking motion in a plane at right angles to the plane of movement of said lever, a block operatively related to said member, and means. for periodically forcing iaid block into engagement with said mem- 5. A sewing machine, embodying therein needle-operating mechanism, controller mechanism therefor including a controller lever, a locking member carried by said lever and capable of rocking slightly in a plane at right angles to the plane of movement of said lever, a block operatively related to said locking member, a support for said 7 block, said block having a rocking motion in 7 controller mechanism therefor including a controller member, and means for forcing said block directly into engagement with said locking member.

6. A sewing machine, embodying therein needle-operating mechanism, controller mechanism therefor including a controller lever, an are shaped locking member carried by said lever and being capableof a slight rocking motion in a plane at rightangles to the plane of movement of said lever, a block-supporting member, a block capable of rocking in said last named mem ber in the plane of said locking member, and means for forcing said block into engagement with said locking member.

7. A sewing machine, embodying therein needleoperating mechanism, controller mechanism therefor including a controller lever, a locking member carried by said lever, a sectional block-supporting member, a block carried by said last named member, means for varying the distance between the sections of said block-supporting member to adjust said block relatively to said locking member, and means, for forcing said block into engagement with said locking member.

8. A sewing machine, embodying therein needle.- operating mechanism, controller mechanism therefor including a controller lever, a locking member movably carried by said lever and capable of rocking slightly in a plane at right angles to that in which the said lever moves, a block operatively related to said locking member, and yielding means for forcing said block into direct engagement with said locking means. 7

9. A sewing machine, embodying therein needleoperating mechanism, controller mechanism therefor including a controller lever, a locking arc movably carried by said lever and'capable} of rocking slightly in a plane at right angles to'that in which the said lever moves, a curved block operatively related to said arc, and a spring arm'for forcing the curved face of said block into direct engagement with said arc.

10. A sewing machine, embodying therein needle-operating V mechanism, controller mechanism therefor including a controller lever, a locker are mounted on said lever and capable of a slight rocking motion in a plane at right angles to the plane of movement of said lever, a sectional block-support, a block movable in said support in the plane of the locker arc, means for varying the distance of the sections of'said support from each other to adjust the block relatively to the locker arc, and a spring arm for forcing said block into engagement with said arc.

In testimony whereof I have hereunto set my hand in the presence of two witnesses. 7

Witnesses:

A. E. ALEXANDER, EDITH HALL.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C.

EDMUND WISEMAN, 

